Relationships between hypercarbic reactivity, cerebral blood flow, and arterial circulation times in patients with moyamoya disease

Abstract

PURPOSE: To evaluate the correlation between angiographic measures of Moyamoya disease and tissue-level impairment from measurements of tissue perfusion and cerebrovascular reactivity (CVR). MATERIALS AND METHODS: The relationship between perfusion-weighted arterial spin labeling (ASL) and hypercarbic blood oxygenation-level dependent (BOLD) CVR and time-to-peak (TTP) were compared with angiographically measured risk factors, including arterial circulation time (ACT) and modified Suzuki Score (mSS) in patients (n = 15) with Moyamoya disease. RESULTS: Hemodynamic contrasts provided information not apparent from structural or angiographic imaging. Mean z-statistics demonstrate that BOLD is significantly (P = 0.017) higher in low mSS hemispheres (z-statistic = 5.0 ± 2.5) compared with high mSS hemispheres (z-statistic = 3.7 ± 1.7), suggesting that regions with less advanced stages of Moyamoya disease have higher reactivity. After correcting for multiple comparisons, a strong trend for a direct relationship (R = 0.38; P = 0.03) between BOLD TTP and ACT was observed, and a significant inverse relationship between CBF and ACT (R = -0.47; P = 0.01) was found, demonstrating that BOLD and ASL contrasts reflect DSA measures of vascular compromise in Moyamoya disease, albeit with different sensitivity. CONCLUSION: Correlative measures between angiography and hemodynamic methods suggest that BOLD and ASL could be used for expanding the diagnostic imaging infrastructure in Moyamoya patients and potentially tracking tissue response to revascularization.